1. Field of the Invention
The present invention deals with tennis net equipment particularly straps for adjusting the height of a tennis net. The present invention also deals with portable net straps which may be used on any tennis net with any tennis court surface having a mount for securing the strap to the court surface.
2. Description of the Prior Art
The game of tennis requires a net stretched across the playing surface in a vertical position at the center of the tennis court from side to side. The end posts supporting the net are positioned outside the sidelines at a height of 42 inches. However, the center of the net is always to be positioned at a height 36 inches above the playing surface of the tennis court.
Many tennis courts, both indoor and outdoor, feature mounts at the center of the court, which mounts are provided to secure a strap about the center of the tennis net so as to adjust the height of the tennis net. These mounts may be staked, cemented, or otherwise sunk in the surface of the tennis court so as to rigidly fix the mount. However, depending upon the type and method of installation of the mount, the point where a tennis net strap attaches to the mount may be somewhat above or below the surface of the tennis court. This creates problems resulting in incorrect measurement.
The game of tennis requires an exact measurement of the height of the center of the net from the surface of the tennis court. If the height of the net is somewhat greater than 36 inches, then an otherwise good tennis shot may strike the top of the net and fall rather than pass to the opposite court. It the net is adjusted such that the top center of the net is somewhat less than 36 inches, then a player's opponent may be able to hit shots into the players court, which shots would otherwise not pass over the net. Even a slight mismeasurement of 1/4 inch or 1/2 inch can make a significant difference in the scoring of the tennis match, especially for experienced players who practice to assure that some shots pass over the net no higher than necessary. Therefore, these players often measure the height of the center of the net to assure that it is precisely 36 inches. This often requires the use of a yard stick or other measuring device which must be brought to the center court to determine the correct height of the net. Many devices have been proposed to aid in net height adjustment.
Bunker, in U.S. Pat. No. 2,296,086 discloses tennis net center band attaching equipment for securing the center of the net to center court and device to overcome the unnecessary gathering of the center of the net at the bottom thereof.
Hardy, in U.S. Pat. No. 1,534,447 shows a strap and attaching buckle for securing the strap over a tennis net to the tennis court mount at the surface of the court. The hook presented by Hardy facilitates securing and releasing the strap from the tennis court surface mount.
Vaile, in U.S. Pat. No. 1,409,981 shows a center stay or tennis nets which is designed to automatically adjust the height of the tennis net to 36 inches above the playing surface. The invention disclosed by Vaile, however, presumes that the tennis court surface mount is disposed such that the net will be positioned at exactly 36 inches when the attaching hook is secured to the mount. Of course, this is contrary to many modern tennis courts where the height or depth of the surface mount at the center of the tenis court may vary as much as several inches from the court surface. Vaile shows no adjustability of the tennis net strap which is required by today's tennis court surfaces and strap mounts.
Robinson, in U.S. Pat. No. 1,351,066 shows an adjustable tennis net strap with buckle device and chain anchoring device. The device disclosed therein is adjustable to the proper 36 inch height of the tennis net when the chain mounting has been appropriately inserted in the tennis court surface and the distance of open link 13 above the court surface is determined. The patent states that the strap (band) is provided with suitably disposed visual indicating means whereby the extent of the adjustment by moving the buckle device can be readily and accurately determined without recourse to a separate measure. This is true, however, only when the height of the chain mount has been determined by using a separate measure. Of course, this device is not useable with a hard surface where a strap mount is already located in the tennis court surface. This device always requires measurement upon installation of the tennis net strap and anchor.
Davis, in U.S. Pat. No. 3,549,146 discloses an anchoring device with a built-in measuring rod which is usable to locate the height of the net at 36 inches when the anchoring device has been properly inserted in the tennis court surface. As with Robinson, the device disclosed by Davis is not usable in a hard surface which has a built-in mount for the tennis net strap. The device of Davis must be mounted in the tennis court surface.
None of the devices of the prior art show a device overcoming all of the problems in the prior art as has been done in this invention. The present invention provides a time saving, portable, low cost device, not requiring its own mount. None of the devices of the prior art contain all of these features and none disclose such a measuring device.
None of the devices in the prior art show a tennis net center strap with the capabilities to adjust and set the height of the tennis net at 36 inches regardless of what height the mount for the strap is set in the tennis court surface. That is, none of the known tennis net center bands and attaching equipment are adaptable to different tennis court surfaces such that some type of measurement must be made to assure that the net is at the proper height.
Therefore, players have often used the method of placing the width of a tennis racquet head on top the length of another tennis racquet to estimate 36 inches for the height of the tennis net. The only alternative to adjusting the tennis net on a court where a mount built into the tennis court surface is to use a yard stick or other device external to the tennis court for measuring the height of the net. This, of course, constitutes a disadvantage, in that, a player must carry a yard stick or other measuring device to the tennis court so as to check the proper height of the tennis net. Since modern tennis courts have strap mounts positioned somewhat above or below the court surface, one of the above mentioned techniques is normally used to align the tennis net. This takes additional time, effort, and materials, thereby detracting from the time available for playing the game. This is especially disadvantageous where players pay an hourly rate for the use of the court.